Comparison of Methods for the Mitigation of Line Disturbances Due to PWM AC Drives

Several methods are used to reduce the line current harmonics created by PWM AC drives, and by doing so, also reduce the voltage distortion at the secondary terminals of the supply transformer. However, each method also impacts the power distribution system in a different way, and has an impact on the operation of the drive itself. This paper will review and compare the effects that harmonic mitigating methods have on the line supply and on the drive. The comparisons are supported by computer simulations of drive systems and verified by extensive tests that were conducted in the lab.